JPS61282023A - Agricultural mulch film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an agricultural mulch film that covers fields, ridges, etc. and adjusts the temperature in the soil to create an optimal environment for the growth of plant roots. .

[Conventional technology]

Currently in Japan, mulch films made of various thermoplastic resins are used. The film is mainly polyethylene film, with a thickness of 7 to 40 μm and a width of 80 to 180 μm.

The effects of mulch cultivation include mulching film on the ground surface to retain soil moisture, maintain soil swelling and softness, prevent fertilizer runoff, suppress disease damage, and increase and control soil temperature.
The aim is to promote early growth, increase initial yield, and stabilize production with high yields.

Figure 1 shows an outline of film mulch cultivation.

In Fig. 1, 1 is a ridge, 2 is a mulch film, and 3 is a plant. 4 is soil that presses both sides of the mulch film 2. When looking at the current mulch films from the standpoint of soil temperature control, their purpose is broad and can be classified into the following two types.

The first type is a film intended to raise soil temperature, and is often used when cultivation is started at relatively low temperatures and in cold regions at high latitudes. The film used is mainly transparent polyethylene film, but in addition to this, polyethylene film colored green or black, or the shoulders of ridges consisting of a transparent part and a black part, is used to suppress the growth of weeds, although the soil temperature decreases slightly. Two-color mulch films that suppress weed growth are also commercially available.

The second type is a film whose purpose is to suppress the rise in soil temperature, and is often used when cultivation is started during relatively high temperatures or for low-temperature crops. A variety of light-reflective, primarily polyethylene-based films are commercially available that are designed to reflect sunlight and reduce solar energy from entering the ground. Representative films are abbreviated below.

■Polyethylene film mixed with aluminum powder (silver mulch film) Contains approximately 2% by weight or more of aluminum powder. Thickness 20~30
Many of them are μ.

■Aluminium-deposited polyethylene film (mirror multi-film) Aluminum is vacuum-deposited on the surface of a polyethylene film approximately 20μ thick on the order of several hundred people. It's expensive.

■Polyethylene film laminated with aluminum foil (aluminum multi-film) A film made by laminating aluminum foil and polyethylene film with excellent light reflectivity. It's expensive.

■Thickness 2 consisting of two layers: white layer mixed with titanium oxide powder and black layer mixed with carbon black powder.
0-30μ laminated polyethylene film (black and white double multi-film) This film was devised by the applicant, and is a material with excellent performance and low cost, and has been registered as a utility model as Registration No. 1382697 (Public Publication No. 55-38369). It is something that exists.

Table 1 shows the maximum soil temperature during the day at a depth of 5 cm underground for representative films of the first and second types that are currently relatively widely used, and the characteristics of each film are clear. The film was laid on a ridge with a ridge width of 60 cm and a length of 5 m, and the soil temperature was measured at the center of the ridge using a thermocouple. The test was conducted at the applicant's Chiba factory in two periods in March and August 1981.

Table-1 Maximum soil temperature during the day with various mulch films is 10
This is a typical example when measured for days. In addition, the transmittance and reflectance of the film were measured using a spectrophotometer model 124 manufactured by Hitachi, Ltd. This is an average value at a wavelength of 400 to 700 nm (visible light). All films were commercially available and had a width of 95 cm.

[Problem that the invention seeks to solve]

In this way, various types of mulch films are used for various crops that take advantage of their characteristics, but if you use only one type of mulch film, for example the first type of transparent mulch film, for the entire cultivation period, It is often observed that inconveniences occur in crop cultivation.

For example, in the Kanto region, mulch is often used during the low temperature period from March to April, and in this case transparent mulch film is often used. This aims to raise the initial soil temperature and promote early growth, including early germination, stable growth, and early establishment. However, in the May-June period, as temperatures rapidly rise, there are many days when soil temperatures reach high temperatures of 35 to 45 degrees Celsius.

You want to raise the soil temperature during the initial growing period, but you want to lower the soil temperature after that, so in such cases, using transparent mulch film alone is not appropriate because the soil temperature will rise too much from May to June onwards. . During this period, the so-called second type of reflective mulch film is better.

As an example of this, when vines are attracted to a high position using supports like Kirari, the ridges are constantly exposed to strong sunlight and exhibit high ground temperatures, which accelerates root aging, causing frequent diseases and shortening the lifespan. Phenomena such as shortening occur. In addition, in the case of crops such as potatoes and canes that accumulate more starch in their tubers and roots, high ground temperatures alone will cause significant respiratory exhaustion and inhibit accumulation.

Contrary to this example, when sowing and planting from the end of July to August, the second type of reflective mulch film, which can suppress the rise in soil temperature, is often used in order to stabilize early germination and growth. However, in this case as well, when we enter the low-temperature period from October onward, we want to raise the soil temperature, so here we will discuss the first
This type of transparent mulch film would be better.

As an example of this, in the case of tomatoes grown under greenhouse control,
By completing the harvest by the end of the year, non-heating cultivation has great economic significance. To achieve this purpose, it is desirable to promote growth by increasing soil temperature from the middle stage onwards.

As described above, the requirements for soil temperature control using mulch are often reversed in the early, middle, and later stages of cultivation, and it is difficult to meet these requirements with the various types of mulch films that are currently available.

Means for Solving Problem C] The present invention solves this problem, and includes a first soil temperature increasing portion A on the above-described film. and second soil temperature suppression part B
An agricultural mulch film characterized by arranging 0 and 0 adjacent to each other in a certain area to form areas with high and low temperatures in the ground to create an optimal environment for the growth of plant roots. be. The shape of the above-mentioned section may be any shape such as circular, triangular, quadrangular, hexagonal, etc.; Basic idea of the present invention.

Detail the content.

The basic structure of the film is shown in Figure 2 (al, (bl,
(The structure is as shown in C1.

As shown in Figure 2 (al), the first
A second soil temperature suppressing type film B is placed in the center of the soil temperature increasing type film A, or on one half of the film A as shown in Figure (b), or on both sides of the film A as shown in Figure (C). It is configured so that it has a direction.

The key point of the invention is the combination ratio of both types of films. That is, in the mold of FIG. 2(a), both types of films A
, B are widths lA and 11I. During mulching, the first type of film A will be pressed down by soil 4 for about 10 to 15 cm on both sides and will go into the soil. Taking this into consideration, the width IA should be 20 cm. The above shall apply.

The width 13 is greater than or equal to loCIB.

In addition, the width 1A is 1. l will go into the soil about 10 to 15 cm on both sides, so taking this into consideration, lA, 1. Both should be 20cm or more.

Further, as shown in Fig. 2 (for the C1O type, the width 7! is 10 cm or more, and the width lll is 20 α or more considering the length of about 10 to 15 ca+ that goes into the soil.

[For production]

Since the film according to the present invention consists of the first soil temperature increasing type film A and the second soil temperature suppressing type film B,
In the ground that covers it, a high temperature part and a low temperature part are formed, so even during the low temperature period from March to April or the high temperature period after May to June, one of the underground parts is in the early stage of plants. It is effective because the temperature on the other side is suitable for late growth, and it can be used in both low-temperature and high-temperature periods, and there is no need to replace the film as in the past, saving labor and materials. It is.

〔Example〕

In the film of the present invention shown in FIG. 2(a), +bl, and (C), the following width βA+7! ll films 5, 6.
7 was manufactured. However, the total width of the film is 120 cm.

Width IA of film A or film B in films 5, 6.7 shown in FIGS. 2(a), (b) and (C) above
Or, the relationship between 11I and soil temperature is shown in the third section. 4. It is shown in Figure 5.

FIG. 3 shows the maximum soil temperature change during the day at 5 cm underground at the center of the film B when the width l of the reflective film B at the center is changed in the case of FIG. 2 [alO type film 5].

Here, a transparent film was used as film A, and a black and white double film was used as film B.

Film 5 is a polyethylene film. The width of the ridge is 1
The measurement was carried out in August 1959.

Figure 4 shows the film 6 of the type shown in Figure 2(b) at the center of part 8 of the film (the center of the ridge surface area, i.e., the soil This figure shows changes in the maximum daytime soil temperature 5 cm underground (excluding the central part of the country). Here, a black film was used as film A, and a silver film was used as film B. Film 6 is a polyethylene film. The width of the ridge is 1m and the length is 5m, 59
Measured in August.

FIG. 5 shows the maximum soil temperature change during the day at 5 cm underground at the center of film A when the width lA of soil temperature increasing film A at the center of FIG. 2 (C1O type film 7 is changed).

Here, a transparent film was used as film A, and a black and white double film was used as film B.

Film 7 is a polyethylene film. The width of the ridge is 1
Measured in March 1959 with a length of 5 m.

In addition, the portion buried in the soil on both sides of the film is approximately 10
It was am.

As is clear from the experimental results shown in Figures 3 to 5 above,
In order for Film A and Film B on the ridge surface to fully exhibit their original characteristics, that is, in order for Film A to raise the soil temperature and film B to completely suppress the soil temperature, Films A and B on the ridge surface must be In either type, the width of each film A and B is at least 10c11 or more, preferably 20c.
It turns out that more than m is required.

Incidentally, the position of the reflective film B at the center of the film 5 of the type shown in FIG.

The same is true for the Cl type film 7 in Figure 2.
The position of the soil temperature increasing film A may be biased to the left or right within a range that satisfies the requirements. The boundary line between films A and B may generally be straight, but it may be meandering (Fig. 6 1a)), zigzag (Fig. 6 (b)), etc., as long as it does not impede the characteristics of both films A and 8. good. Furthermore, Figure 6 (C), (d)
It may also be a cut pattern in the shape of a narrow slit (for example, about 2 to 4 cm wide) as shown in FIG.

Further, in the film of the present invention, since the film is pressed with soil during mulching, the film is buried approximately 10 to 15 cm into the soil, and is completely unrelated to soil temperature control. Therefore, as long as the film portion on the ridge substantially meets the conditions of the present invention, both side portions, that is, approximately 10 to 150 portions on both sides, may be of either type A or B. I don't mind.

The first soil temperature increasing type film A may be a transparent, green, black, etc. film, and the second soil temperature suppressing type film B may include various types of light reflective films such as silver films, mirror films, etc. Film, aluminum film, black and white double film, etc. can be applied. Furthermore, as shown in FIG. 7, surface B, which has the same structure as the black and white double film, is made of a silver reflective layer (containing aluminum powder),
A so-called silver-black double film in which the lower surface B (ground side) is a black layer for weed prevention can also be applied as film B.

The most common base material for mulch film is polyethylene resin, but various thermoplastic resins such as polyvinyl chloride, polyester, and nylon can also be used.

These may be used alone or in an appropriate blend of two or more.

Stabilizers are commonly used additives.

Antioxidants, plasticizers, lubricants, fillers, etc. may be added as appropriate.

The method for producing the film of the present invention is the above film A.

Any suitable method that can be considered at present depending on the combination of B may be used. For example, two-color extrusion molding method (inflation method) consisting of transparent and silver, transparent and black and white, etc.

T-die method), or a printing coating method such as printing silver on a black film, a laminating method such as adhering aluminum foil to a black film, or a vapor deposition method such as transparent film hair niminium vapor deposition, and film A and film Various methods can be applied, such as a method in which B is made separately and bonded together by heat sealing or the like in a separate process.

The thickness of the film should be determined within a range that satisfies the strength, price, etc. for multipurpose use, and is approximately 5 to 3.
It may be in the range of 0μ.

In addition, in order to adjust the soil temperature, the film has small holes (with a diameter of 5 mm or less) and cuts (cut width of 4 mm), especially in the light-reflecting film part of Film B, for the purpose of lowering the soil temperature by latent heat of evaporation.
(approximately 0 or less) may be provided as appropriate.

Next, a method of using the film according to the present invention will be explained.

In general, the optimum temperature for plant roots is between 20 and 30 degrees Celsius; if the temperature rises too much, oxygen in the soil decreases, and at 35 degrees Celsius it is half of what it was at 15 degrees Celsius, inhibiting root activity. Due to high humidity, the same damage as during flooding occurs, that is, yellowing and deterioration of the roots, which causes the roots to breathe more, causing depletion and deterioration of the roots.

Also, in the early stages of plant growth, raise the temperature of the soil.
During this period, creating a cool area underground will effectively store the assimilated products. Therefore, plants may be sown or planted in each film A or B portion according to the cultivation period.

When planting seedlings in the high temperature period of midsummer and harvesting them in the shade from late autumn to early winter, such as in the case of suppressed cultivation of high-temperature crops (tomatoes, cucumbers, green peppers, eggplants, etc.), seedlings are planted in midsummer (July), such as suppressed tomatoes. are planted and harvested from autumn to winter,
In the case of summer-sown, winter-harvested, low-temperature crops, it is suitable to plant them in section B of the film 5 shown in FIG. 2 fa) and the film 6 shown in FIG. 2 (b). Soybeans (edamame) are examples of such low-temperature crops.

Examples include radish, Chinese cabbage, lettuce, spinach, carrot, cabbage, and potato.

On the other hand, those that are sown in spring and harvested in summer, such as sweet potatoes, taro, corn (sweet corn), watermelon, melon, cucumber, eggplant, and tomato, are shown in Figure 2 (Film 6 and Figure 2 in BL). It is preferable to plant the seeds in the A section of the film 7 shown in (C).

In the above-mentioned typical embodiment, the soil temperature rising portion ◯ and the soil temperature suppressing portion B0 are placed adjacent to each other in the longitudinal direction, but the present invention is not necessarily limited to this.

8 to 11 show still other embodiments of the present invention.

The film 9 shown in FIG. 8 has a plurality of circular soil temperature increasing portions marked with circles inside the soil temperature suppressing portion B0. 9th
On the contrary, the illustrated film 10 is provided with a plurality of circular soil temperature suppressing portions B0 in the circle where the soil temperature increases. 1st
The film 11 shown in FIG. 1 has square parts diagonally adjacent to each other like a chess board, one of which is a soil temperature increasing part AO and the other part is a soil temperature suppressing part B0. The film 12 shown in Figure 11 has one of the adjacent parts, like a diamond game board, connected to the part where the temperature of the ground increases. , the other is the soil temperature suppression part B0
That is.

Here, the size and shape of the portions Ao, 80 in the examples illustrated in FIGS. 8 to 11 are as follows:
B.

It is sufficient that the soil temperature control characteristics of 1 are substantially fully exhibited.

The size of each part will be considered based on the relationship between film width and soil temperature shown in Figures 3 to 5. For example, the film 9 shown in FIG.
Go to the circular part in part B. When sowing or planting in part ○, the size is from the center of planting hole 8 to part 4.
Straight road to the end of 0th lap! 1111, 1.

. . . is 5 cm or more, preferably 10 cm or more. That is, the size and shape may be such that the planting hole 8 can be provided to meet this condition.

Other embodiment shapes may also be used as long as they satisfy this condition.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to create an optimal environment for the growth of plant roots by regulating the temperature in the soil, and it is possible to effectively cultivate plants.

[Brief explanation of drawings]

FIG. 1(a) is a perspective view showing the state in which the agricultural mulch film according to the present invention is applied, FIG. 1(b) is a cross-sectional view thereof, and FIGS. The explanatory diagrams of the examples and Figures 3.4.5 are graphs showing the relationship between the film width and the maximum soil temperature during the day for the three examples above. Figures 6 (a), (b), (C1, d) is a plan view of another embodiment of the present invention, FIG. 7 is a sectional view of an embodiment of soil temperature suppressing type film B, and FIG. 8.9.10.11 is a plan view of yet another embodiment of the present invention. These are the diagrams. (C) (d) Ship/?Medice θ- Paper 9 life σ Raku 10 area $1 day

Claims (1)

[Claims] A first soil temperature increasing portion and a second soil temperature suppressing portion are arranged adjacent to each other in a certain section on the film to form a portion with a high soil temperature and a portion with a low soil temperature in the ground, thereby creating an environment optimal for the growth of plant roots. An agricultural mulch film characterized by making.